1. Field of the Invention
This invention relates to a green refresher, that is, a soil tiller or cultivator adapted to till the surface soil covered with lawn or green to cure the compaction of the soil below the lawn surface. More particularly, it relates to a green refresher provided with a cutter driving unit which may undergo only small oscillations or vibrations and which is suitable for refreshing the green or lawn of a golf field.
2. Description of the Prior Art
In a grassy area, such as a lawn, the ground surface is trodden under foot and tramped as time elapses so that the growth of the lawn is obstructed.
For these conditions, a tiller or cultivator provided with vibrational cutters has been used extensively. With the cutters penetrated through to the core soil below the surface soil from above the lawn surface, the cutters are moved as they are imparted vibrations and oscillations so as to till and crush the tramped soil to cut the old roots as well as to cause the moisture, oxygen and the fertilizer to be penetrated deep below the ground surface.
For such purpose, a tiller provided with plural juxtaposed cutters has been used extensively for improving the operating efficiency.
However, in the conventional device employing a plurality of juxtaposed cutters, oscillations or vibrations are imparted to the cutters at the same phase, that is, simultaneously and in the same direction. In such case, the energy of oscillations of the cutters and the force of resistance or reaction that is produced by the friction of the oscillating cutters in the soil are increased with an increase in the number of cutters. For this reason, in the conventional tiller making use of plural juxtaposed cutters, extremely large vibrations are transmitted to the operator's hands through the main body of the device, such as handles, while extremely large noises or creaky sounds are produced.